Mangrove Ecology

Mangroves are forests that dwell along tropical and subtropical coasts and provide a link between the sea and land. Both locally and globally, they provide a basis for teh production of food, and local communities use them as a source for wood extraction. From an ecological perspective, they support a detritus-based food web through exporting their leaf litter into estuarine and coastal waters, where it supports a plethora of marine life that uses mangroves as shelter, migration site or nursery. The accretion and stabilization of sediments contribute to protecting teh coasts from erosion and storm surges. Being popular touristic sites, they offer aditional income for local people.

Mangroves are among the most efficient CO2-sinks: because of their high productivity, they store more carbon and nitrogen in their biomass and the sediments than many other ecosystems. Hence, they potentially contribute to mitigating climate gas-driven climate change.

Almost worldwide, mangroves are threatened by human use and exploitation - e.g., wood extraction and clear-cutting, pollution and eutrophication of rivers and coastal waters, dredging and diking for land-claiming- as well as by the ongoing (relative) sea level rise. Annual area losses range among 2-8 % of the worldwide mangrove area, and within the next 100 years, mangrove might be entirely lost.

Besides the direkt loss of biodiversity and ecosystem services, the ongoing loss of mangroves exhibits indirect effects on adjacent ecosystems, such as seagrass meadows or coral reefs, that suffer from increased sedimentation upon removing mangroves. Further, the destruction of mangroves eradicates breeding- and nursery areas of numerous marine species.

Through observational, experimental and modelling approaches, the Mangrove Ecology Group aims at providing a scientifically sound basis for the sustainable use, management and conservation of mangroves worldwide.

Our aim is to provide a reliable scientific fundament for the protection and the sustainable use of mangroves that can serve as guideline for stakeholders and decision-makers for the planning and management of protected areas:

For this, knowledge and in-depth understanding of the ecosystem is required - Which organisms occur under which environmental conditions (biodiversity)? How do organisms interact (biotic interactions), and how to they respond to environmental change? How will the ecological community change, when the environment and resource-use by humans will change (model-based projections)? Which processes are currently driven by the community, and how will this change in the future (ecosystem processes)? Which ecosystem services result from these processes, how are they utilized by whom (social-ecological systems analysis), and how can their use be rendered sustainable (conservation-prioritization, -planning and -management)?

We describe mangrove communities with the aid of classical faunistics and floristics but also through metabarcoding (and metagenomics) of environmental (and microbial) DNA. Correlations between community composition and environmental conditions are translated into models that project future future mangrove communities in space and time. With a focus on sediment processes and dynamics, we analyze the chemical structure (metabolomics: (py-)GC/MS; NIRS) and the dynamics (transcriptomics) of organic matter and quantify fluxes (export/import) of elements and nutrients (micro-sensors). Further, we study the accretion and erosion of sediments as they depend on mangrove community composition.